Scientists in the U.S. think they may have solved the puzzle of why some embryos fail to implant in their mother's womb, which is one of the main causes of IVF failures.
Scientists have discovered a key step in implantation that they believe could improve success rates.
The team, led by Jerold Chun of the Scripps Research Institute say molecules called receptors that lock on to the lipid - lysophosphatidic acid, or LPA - are a "drugable target" for pharmaceuticals able to enhance female fertility. The process involves a lipid, or fat, that helps regulate the timing of the vital first stage of pregnancy.
To find the LPA "signalling pathway", Dr Chun and his team studied implantation in mice with and without LPA. They discovered that without LPA to trigger biochemical events, the timing of implantation was delayed.
Research has found that embryos may implant in the wrong place, fail to form correctly, break down or show retarded development and placentas may form incorrectly. He thinks a substantial search will be needed for similar candidate molecules in people.
Sudhansu Dey, of Vanderbilt University in Nashville, Tennessee, suggests that other biochemical pathways may act with LPAs to ensure implantation but says it is clear that fat matters to fertility.
The report from researchers from the US and Japan is published in the journal Nature.